How the next tier of strict en­vi­ron­men­tal regs could pave the way for su­per­charged 600s, wide­spread VVT and even a glut of hy­brid sports­bikes

Performance Bikes (UK) - - Contents - Words Ben Purvis

Stricter emis­sions reg­u­la­tions open the flood­gates for su­per­charged sports­bikes

UN­LESS YOU’VE been liv­ing in a cave for the last cou­ple of years you’ll be fa­mil­iar with the term ‘Euro 4’. The cur­rent Euro­pean emis­sions lim­its for bikes came into force in two stages – newly type-ap­proved mod­els had to com­ply from the start of 2016 and carry-over bikes had to be up­dated to meet the lim­its from Jan­uary 1, 2017.

For man­u­fac­tur­ers, it’s old news; all bike en­gi­neers’ eyes are now firmly on the next-stage ‘Euro 5’ lim­its which rep­re­sent a much big­ger step. But could stricter reg­u­la­tions spell the end for sports­bikes – or force man­u­fac­tur­ers to try new ideas? PB takes a close look at what Euro 5 means for new bikes. Don’t panic – it’s not all doom and gloom.

Farewell tra­di­tional 600s

Euro 4’s emis­sions de­mands have had the big­gest im­pact on sports­bikes. Some bikes re­quired ex­pen­sive en­gine re­vi­sions to bring them into line, and if that model’s sales aren’t high enough to jus­tify the in­vest­ment there’s only one other course of ac­tion; they’re axed – 600cc su­per­sport bikes in par­tic­u­lar be­ing dec­i­mated.

The Euro 4 reg­u­la­tions are tough, par­tic­u­larly for high-revving, high-pow­ered, small-ca­pac­ity en­gines. Firstly, there’s the straight­for­ward cut in emis­sions lim­its – the lat­est rules slash car­bon monox­ide from 2.0g/km to 1.14g/km, hy­dro­car­bons from 0.3g/km to 0.17g/km and NOx from 0.15g/km to 0.09g/km. But Euro 4 also in­tro­duces a rule that bikes must still pass the new lim­its af­ter 20,000km or 35,000km (de­pend­ing on en­gine size), com­pared to just 1000km un­der Euro 3. So a brand new en­gine needs to be around 30% un­der the le­gal lim­its to give head­room for it to de­te­ri­o­rate and still beat the re­stric­tions with mileages equiv­a­lent to many years’ av­er­age use.

Scream­ing four-cylin­der 600s rely on high revs to achieve their power, which has a cou­ple of prob­lems. One is that they wear more over the same mileage when com­pared to a lower-revving en­gine. Worse, they need a lot of valve over­lap – the pe­riod when the in­let valve opens be­fore the ex­haust valve has closed – to op­er­ate at high revs. While it makes for clean run­ning at peak revs, that valve over­lap means emis­sions tend to be worse at lower revs, where the emis­sions are tested. It can be fixed, but only by adding ex­pense; costlier cat­alytic con­vert­ers, for in­stance. Clever en­gine sys­tems like vari­able valve tim­ing would make for an emis­sions-friendly 600, but de­vel­op­ment/build costs would be the same (or more) than a 1000cc su­per­bike, and since sales of 600s are al­ready slow, there’s lit­tle case to be made for mid­dleweights cost­ing £15,000.

So what changes for Euro 5?

So, we might be say­ing good­bye to tra­di­tional, scream­ing 600s. But superbikes are still OK un­der Euro 4, right? Yes. All the ma­jor man­u­fac­tur­ers ex­cept Du­cati have up­dated their superbikes to meet the new rules. The 1299 Panigale is be­ing sold un­der the ‘end of se­ries’ regs and will soon be re­placed by a new range-top­ping Du­cati, prob­a­bly a Des­mosedici-de­rived, 1000cc four-cylin­der.

But Euro 5, like most se­quels, will be rather worse than its fore­bears. And it’s not far away; the cur­rent plan is to bring it in for new mod­els at the start of 2020 and to get man­u­fac­tur­ers to make the rest of their bikes com­ply by Jan­uary 1, 2021.

How much worse? The num­bers show a rel­a­tively small cut in CO lim­its but a big slash in hy­dro­car­bons, down from 0.17g/km to 0.1g/km. NOx is cut from 0.09g/km to 0.06g/km. There’s also a new limit, for non-meth­ane hy­dro­car­bons, at 0.068g/km (68% of the to­tal hy­dro­car­bons). That’s vastly less than cur­rent bikes man­age and will pose an even larger prob­lem to en­gines with lots of valve over­lap. Like ev­ery cur­rent four-cylin­der su­per­bike...

The over­lap dilemma

No, this isn’t a dire warn­ing that the sky is fall­ing. But superbikes in fu­ture might be quite dif­fer­ent – in a good way.

To get a les­son on where tougher emis­sions lim­its will lead, the sim­plest thing is to look at the way cars have de­vel­oped over the last few years. On four wheels, Euro 5 is a dim mem­ory – today’s cars are al­ready on even harder Euro 6 re­stric­tions.

Mod­ern cars widely use vari­able valve tim­ing, and bikes are slowly catch­ing up. Kawasaki’s GTR1400 has had sim­ple, hy­draulic cam-phas­ing VVT (which ad­vances or re­tards the in­let cam tim­ing de­pend­ing on revs) for a decade. Du­cati is slowly spread­ing sim­i­lar cam phasers, on both in­take and ex­haust, through its Tes­tas­tretta 11 twin-cylin­der range. And for 2017, Suzuki has be­come the first to field a VVT su­per­bike, us­ing a clever in­let cam phaser that em­ploys cen­tripetal force rather than hy­draulics – a sys­tem the Ja­panese fac­tory has used in Mo­toGP to dodge reg­u­la­tions that ban hy­draulic or elec­tronic VVT set-ups.

So VVT is al­ready here and will only get more wide­spread. It will fol­low in the foot­steps of things like fuel in­jec­tion and fly-by-wire throt­tles, which both were well es­tab­lished for emis­sions pur­poses in cars be­fore they mi­grated to bikes.

Suzuki has be­come the first to field a VVT su­per­bike, us­ing a clever in­let cam phaser that uses cen­tripetal force rather than hy­draulics

Tur­bocharg­ing the fu­ture

Tur­bos have made a mas­sive come­back in the car world thanks to Euro 5 and Euro 6, al­low­ing man­u­fac­tur­ers to down­size their en­gines and add un­prece­dented com­bi­na­tions of per­for­mance and fuel econ­omy. The com­bi­na­tion of mod­ern elec­tronic con­trol sys­tems, small, light tur­bos and fly-by-wire means that they can be just as sharp as a nor­mally-as­pi­rated mo­tor.

On the turbo front, Suzuki has so far been the most out­spo­ken. In 2013 it showed the tur­bocharged Re­cur­sion con­cept – a 588cc par­al­lel twin. Although it only claimed a mod­est 100bhp, at 74lb.ft the en­gine’s torque was in the su­per­bike league. In 2015, the firm re­vealed a much more pro­duc­tion-ready turbo en­gine. Again it was a par­al­lel twin, but quite un­like the Re­cur­sion’s. Where that con­cept used a sim­ple SOHC lay­out, the new en­gine, dubbed EX7, was a DOHC mo­tor with larger, but still se­cret, ca­pac­ity – the ‘7’ per­haps hint­ing at 700cc.

Like Kawasaki, Suzuki is ex­pected to use the bi­en­nial Tokyo Mo­tor Show at the end of this year to re­veal the next stage in its progress to­wards a whole new class of forced in­duc­tion bike. The firm has been open about the fact that its turbo en­gine is mov­ing to­wards pro­duc­tion. It’s likely that it will even­tu­ally power a whole range of mod­els.

Su­per­charged as­sault

Car firms again – faced with their own set of ever-tough­ing emis­sions and econ­omy tar­gets – have jumped on to the su­per­charg­ing band­wagon, cre­at­ing mon­strous en­gines with un­prece­dented power fig­ure at a sur­pris­ingly rea­son­able cost. Chevro­let’s bluecol­lar Ca­maro can be had with a 6.2-litre

Suzuki have so far been the most out­spo­ken on tur­bos, show­ing a 588cc par­al­lel twin in 2013

su­per­charged V8 mak­ing 640bhp and 640lb.ft...

Kawasaki has spent mil­lions on de­vel­op­ing bike-spe­cific su­per­charger tech­nol­ogy. The Ninja H2 might be a dream bike to most, but its tech is likely to fil­ter down to more main­stream ma­chines in the near fu­ture. Like tur­bos, su­per­charg­ers have the po­ten­tial to make smaller, more ef­fi­cient, lower-emis­sions en­gines per­form as well as – or bet­ter than – today’s larger units. De­spite its per­for­mance ad­van­tage, the H2's emis­sions ate lower than a ZX-10Rs

Fu­ture su­per­charged Kawasakis might well have smaller cylin­der count. For in­stance, a mid-sized win – say 650cc, like Kawsaki’s Ninja 650/Z650 mod­els – with a su­per­charger at­tached could be airly eas­ily de­vel­oped to make the same sort of ower and torque as today’s 1000cc superbikes, with the po­ten­tial added ben­e­fit of lower weight. Kawasaki is widely ex­pected to re­veal its

sec­ond-gen­er­a­tion su­per­charged bike later this year, although ex­actly what form it will take is still a se­cret. Honda, while it hasn’t shown any­thing of­fi­cially yet, has al­ready been work­ing on su­per­charged twin-cylin­der de­signs. The firm has filed a host of patents for su­per­charged par­al­lel twins, some ap­pear­ing to be based on the NC750 en­gine, oth­ers look­ing more like a VFR1200F’s V4 with the rear cylin­der bank sliced off and re­placed with a su­per­charger.

Even Nor­ton has plans to get in on the forced in­duc­tion ac­tion. The Bri­tish com­pany has en­gaged en­gine firm Ri­cardo to de­velop the 1200cc V4 in its new su­per­bike, but is also at work on a 650cc par­al­lel twin – ef­fec­tively half the new V4, with a slight ca­pac­ity stretch – which it hopes to de­velop to in­clude a su­per­charged ver­sion.

Best of both worlds

While forced in­duc­tion and VVT are the two con­cepts clos­est to mak­ing big changes to the bikes we buy, other tech­nolo­gies proven in cars are also mak­ing a move to­wards two wheels. One is hy­brid power, com­bin­ing a down­sized petrol en­gine with an elec­tric mo­tor. While the word ‘hy­brid’ evokes im­ages of holier-than-thou ar­se­holes driv­ing a Prius, it’s worth bear­ing in mind that the lat­est crop of multi-mil­lion pound hy­per­cars have all used hy­brid tech in pur­suit of earth-shat­ter­ing per­for­mance while re­main­ing emis­sions-le­gal. The Porsche 918 Spy­der and McLaren P1 both take the same route. Again, it’s un­der con­sid­er­a­tion for bikes. Honda has filed sev­eral hy­brid patents, although is more likely to use the sys­tem on a large tourer than a sports­bike.

Suzuki’s hy­brid de­vel­op­ments in­clude per­haps the most ex­treme su­per­bike yet – a tur­bocharged four-cylin­der with an elec­tric mo­tor that helps add even more power and fills in any re­main­ing turbo lag or holes in the power­band. Only re­vealed in patents so far, it shows how se­ri­ously man­u­fac­tur­ers are tak­ing the new tech­nol­ogy.

Scream­ing fours aren’t doomed

In the shorter term, we’ll see a grad­ual shift to­wards dif­fer­ent tech. Euro 5 in 2021 won’t in­stantly draw a line un­der four-cylin­der superbikes, but it’s likely to al­ter the del­i­cate bal­ance of cost and re­turn for man­u­fac­tur­ers, tip­ping some in favour of boosted, lower-revving, smaller-ca­pac­ity de­signs with a lower cylin­der count. Far from re­strict­ing the range of op­tions, we’ll prob­a­bly see a wider choice of so­lu­tions.

Which­ever so­lu­tion bike mak­ers opt to pur­sue, the clear les­son from the car in­dus­try is that we should ig­nore dire warn­ings of re­duced per­for­mance or spi­ralling costs. Cars today are more pow­er­ful, more eco­nom­i­cal and of­fer more per­for­mance-per-pound than ever be­fore. The same will ap­ply to fu­ture superbikes, re­gard­less of their en­gine size or lay­out. One day we might look back at four-cylin­der, nat­u­rally-as­pi­rated sports­bikes in the same way as we do a two-stroke Suzuki RG500 now; with warm me­mories but safe in the knowl­edge that the lat­est stuff is many times bet­ter.

Cars today of­fer more per­for­mance-per-pound than ever. The same will ap­ply to fu­ture superbikes

Suzuki’s tur­bocharged ‘Re­cur­sion’ con­cept has since evolved into the DOHC ‘EX7’ Kawasaki’s su­per­charged, nut­case H2 is ac­tu­ally cleaner than the firm’s ZX-10R su­per­bike

Du­cati has dis­pen­sa­tion to keep sell­ing the non-Euro 4-le­gal Pani, for now...

The 2017 Suzuki GSX-R1000’s VVT is the first on a pro­duc­tion su­per­bike. But this sys­tem will grad­u­ally be­come more wide­spread The costs in­volved in keep­ing 600s like the ZX-6R com­pli­ant sim­ply don’t add up when you take the sales fig­ures of su­per­sport...

Honda patents clearly show they’re se­ri­ous about su­per­charged twin-cylin­der de­vel­op­ment Suzuki’s four-cylin­der turbo is planned to use an elec­tric mo­tor to add even more power. Hy­brid bikes? Yes please...

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